Commencing with the introduction of the personal computer over a decade ago followed by the development of higher and higher function stand-alone workstations over the subsequent years, the user constituency has dramatically changed. From a relatively small number of computer and program literate users, the number of computer users throughout the industrial world has increased several orders of magnitude to include rapidly increasing groups in all fields of endeavor, e.g. students even at the elementary school level, small store owners, truckers, as well as professionals in virtually all fields e.g. doctors, accountants, designers of various products etc.
Relatively few of these users have a great interest in computers except for what it can do for them as a tool in carrying out their professional or other functions. Consequently, their computer literacy level may be expected to be at a relatively low point. Recognizing this situation, the computer industry has been striving to make the interfaces between such users having only casual computer interests and the application programmed computer to be as user friendly (i.e., simple as possible).
The application program orchestrates the PC or workstation computer to perform the combination of functions or jobs which the user needs it to perform. The interactive display screen has traditionally been the means through which the user provides his input to the application program and the application program provides its output to the user. Originally, this interface was a relatively complex one requiring a user who was computer literate. He had to be familiar with the exact instructions needed to input or extract data from the application program. However, with the proliferation of PC and workstation users who were not very computer literate, the trend has been to make the interface as user friendly as possible. Screen panels explaining simply every I/O step relative to the application program and help screen with further information were available at the touch of a key, and icons were included to increase the user's familiarity and recollection.
It followed, however, that as the interfaces became more and more friendly and simplified, the design of the sets of screen panels required for such user friendly interfaces became more and more time consuming, complex and tedious. For example, an I/O exchange with an application program which if designed for a computer literate user might consume one or two panels, could require 10 or 15 panels with layouts which are relatively complex to design when used for a user friendly interface with a user who knew little about computer languages.
It was not unusual for designers of user friendly interfaces with application programs to have to design several hundred or more screen panels in order to provide a user friendly interface with that application program. This presented a lengthy and tedious task for the display screen panel designer. He usually had to design each panel individually, almost exactly laying out each of the components in the panel along selected X,Y coordinates. This further required a fair amount of layout skills on the part of the designer in order to provide some consistency in layouts from panel to panel.
Thus, it can be seen that the creation of a set of panels used to implement the I/O interface with an application program required a considerable expenditure of resources. It often required a lengthy and tedious effort by an individual who had both considerable computer skills as well as layout and graphical skills.